From Ben Stoegers website
"Fits IPSC box in Standard Division, with Original spring and follower with no modifications, reach 17 rounds in .40SW"
http://benstoegerproshop.com/egd-xtreme-eaa-tanfogolio-witness-base-pad-basepad-by-eric-grauffel/
More pics
https://secure.arnzenarms.com/product/european-american-armory/uspsa-guns/3-gun/idpa/uspsa/tanfoglio-eaa-witness-xtreme-match-40-sw-6-inch-barrel-single-action-fiber-front-sight-adjustable